For a pair of young successful Hong Kong entrepreneurs, Felix Chung and Alex Tam talk a lot of rubbish.

'In Hong Kong, recycling is still at a very low level,' Chung said from a makeshift office above a recycling depot in Kwai Fong. The depot, which accepts more than 40 types of recyclable materials, is one of two community recycling centres set up by Chung and Tam's company, EcoSage.

The pair, former environmental engineers who left their safe and secure corporate careers in 2005, have led EcoSage to double in size in five years and now have eight people on their payroll. They recently won an award for environmental entrepreneur of the year from The Prince's Youth Business International, a non-profit organisation that supports young entrepreneurs worldwide.

'Both of us wanted to be entrepreneurs, but we didn't know how to start a company and which industry to start it in,' Chung said. Quitting their careers was a hard decision to make, he said. 'You have lots to consider. Before we started EcoSage, we had jobs, the security of pensions, a career path.'

Tam was 28 then and Chung was 35. Chung said: 'I've got a family to support and I'm the only male in the family, so the expectations were high especially because we've got a 'better education' background.'

They spent six months researching the city's recycling industry. The turning point came when they found out about Youth Business Hong Kong (YBHK), an organisation that offers seed funding to entrepreneurs aged between 18 and 35 years.

The duo used their HK$80,000 loan from YBHK to open their first depot in Ngau Tau Kok in 2005 before expanding to Kwai Fong last year.

Chung said their business model was successful because the depots were clean and easy to use, and the process of submitting used items took less than a minute.

The street-level entrance means people can simply walk in and place their goods on a weighing station. Staff calculate the value of the goods according to the weight and the person is paid in cash. The depots accept paper, metals, cans, electrical appliances and used clothes. A price list displayed at the entrance shows how much different materials are worth.

'That way, we can have transparency,' Chung said.

Before the depots opened, they sent information about recycling to residents living within 150 metres of the site. 'Residents are a new category of customers,' Chung said, in contrast to rag-and-bone men and cleaners.

EcoSage recycles about 200 tonnes of paper and up to five tonnes of non-ferrous metals per month. Paper waste is sent to mills on the mainland, but Chung and Tam hope to open a paper mill in the city. 'There's lots of room to improve,' Tam said.